Tracker-bar for pneumatic players for musical instruments.



PATENTER Nov. 1s, 1906.

(RP. BRAND. TRACKER RAR EORENEUMATIG PLAYERS EoR MUSICAL INSTRUMENTS.

APPLICATION FILED I'BB. 23. 1905.

MIM!! lUNITED STATES :PATENT- OEEIOE.

' N. ears,776.

Specification of Letters Patent.

Patented Nov. 13, 190e.

Application filed February 23.1905, Serial No. 246.865.

v.To all whom it may concern."

Be it known that I, GEORGE P. BRAND, a citizen of the United States, residing in the cityv of New York, borough of. Manhattan,

vcounty andfSt'ate of New York, have invented certain new and useful Im rovements in Tracker Bars for Pneumatic P ayers for Musical Instruments, of which the following is a specification. v

- kMy improvements relate to what are known as bridges or trackerbars in pneuf vmatic apparatus, such as piano and other musical instrument players, inwhich aperforated tune-sheet is employed. v

-The object of my invention is to attain a tracker-bar in which the adjoining note-holes are as close to each other as it is practicable to makethem, so that a comparatively narvrow music-sheet may be used. The mven- Fig. 1.

tion consists in the construction herein de scribed and claimed specifically.-

In the accompanying drawings, Figure 1 is a top view of 'a portion of my improved tracker-bar broken away in part. Fig. 2 is a side elevation of thel same with a detachable cover in place; Fig. 3, a like view with the detachable cover removed. Fig'.` 4 Ais a transverse section taken upon plane of line v4 4, Fig. 5 is a side elevation of a portion of the trackerfboard, illustrating the use of a ilexible detachable cover for thevent-chamber. Fig. 6 is a section of a portion of the tracker-board', taken upon plane of line 6 6,

Fig. 4. Fig. 7 is a section on plane of line 7' 7, Fig. 2. I

It is a well-known fact that for reasons which need not be entered into here it is eXpedient to have each bleed-hole as near as practicable tothe note-opening in the face of the tracker-bar, and for this reason I make m ventlchambers o directly in the body of the tracker-bar itself,'one on eachvsidethereof. The tracker-bar is made to accommodate a y relatively'large number of note-'holes fn, in a given length--as, say, fourteen or sixteenl to the inchthe individual ducts d being arranged alternately on op osite sides of the row of such note-holes 1n order to afford ducts of la prescribed diameterl sufficient to accommodate the tubular conduits d-that is to say, as shown in Fig. 4, the note-holes n o en into the primary ducts d, in each case c osed on one side thereof, so that by alternating the rimary ducts on opposite sides of the row Ofp made to approximate each other more note-holes n the lattermay be' closely, the primary ducts on one side of the central line of note-holes fn, communicating with the vent-chamber 'v on that side of the bar, While the primary ducts on theother side of saidy center. communicate with thel corresponding vent-chamber on the other side of the bar. y i

Each vent-chamber consists ofa groove formed and extending longitudinally in a side of the tracker-bar T, said groove being per.

manently closed at either end and `commun1- y v eating through a suitable duct o with a tension-chamber. 1

Each primary duct dis preferabl made by drilling nearly through 'the bo y of the tracker-board T from its inner or under side, only a relatively thin web t or thickness of material being left at the face of the board, through which the relatively small hole n is formed, and each duct d being put in communication with a primary valve or pneumatic by means of a suitable tube or conduit d gin any well-known'or desired manner...

The depth of the vent channel or chamber o is preferabl such as to leave but a oomparatively thin wall between it andthe adjacent side of each of the primaryducts d with which it is to communicate, so that the bleed-hole b in ay be very shallow, as well asof minimum diameter, thus increasing its sensitiveness and efliciency and rendering it less liable to become clogged. The vent groove Or chamber o is closed from end to end b may a detachable cover c. lThis cover c e constituted inV various ways, the' main essential being that it shall hermetically seal the vent-chamber when in place `and at the same time be detachable from the tracker-bar. Thus as illustrating two extremes of construction the cover c may `consist of a plate attached by screws c to the side of the tracker-bar with packing p interposed between the `opposed surfaces, as in Fi s. 2, 4, and 7, or it ma co'nsist of a strip of eather or -other suitab e iiexible material secured in position upon the tracker-board b shellac or by any other suitable means, as

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il ustrated in Fig. 5. A detachable cover` made of metal and packed with leather is desirable in most cases; but where the trackerbar is not visible externally, as in automatic or slot "machines, leather and shellao maybe used for the' sake of economy, the leather being easily detached by stripping' andas -rllelaflllily replaced by the'use of additionall s e ac.

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By forming thevent-chamber and bleeds directly Within the body of the tracker-bar and closing thev vent-chamber by means of a detachable cover I facilitate access to the bleed-holes, and thereby greatly lessen the cost ofkeeping the apparatus inrunning order by dispensing with the need of skilled l labor in case of obstruction in any of the bleed-holes;

By reference to the drawings it will be seen vthat with the exception of the detachable covers c my tracker-bar is madein one piece with the relatively small note-holes a in a longitudinal row, which is preferably central on the'face of the bar and with the relatively large laterally-disposed primary ducts d alternating on either side of said central lon- V gitudinal row of note-holes a, 'the vbleedholes for each duct d connecting directly with the longitudinal vent-chamber u in the adjacent side of the bar, as shown clearly particularly in Figs. 4 and 6.

What I claim as m invention, and desire to secure 'by Letters gatent, is-

1. In pneumatic apparatus, a tracker-bar formed in one piece `with a longitudinal row 'of relatively small'note-holes, and with a seof note-holes and each having a note-hole opening into it' at its side next the central row of note-holes, whereby the distance between the adjacent note-holes is reduced to the minimum as set forth, said tracker-bar also having a longitudinal tension-chamber vformed directly in each side Wall, each of said tension-chambers being connected by bleedholes with the primary ducts on that particular side cf the central row of note-holes, substantially as and for the purpose set forth.

3. In pneumatic apparatus, a tracker-bar formed in one piece with a longitudinal row of relatively small note-holes, and with a series of relatively large cylindrical primary ducts for the reception of tubularconduits, said cylindrical primary ducts being formed vpose described.

u in the body of the bar by boring through the under side of said bar alternately on oppo- Asite sides of said longitudinal row f noteholes which latter are bored through the thin web left at the face of the bar, each note-hole entering one of the cylindrical ducts on the side thereof adjacent to the said longitudinal row of note-holes, whereby the cylindrical ducts are arranged in close proximity to each other, and the distance between adjoining note-holes is reduced to theminimum for the purpose described.

4. In pneumatic apparatus, a tracker-bar l formed in one piece with a longitudinal row of relatively small note-holes, and with a series of relatively large c lindrical 'primary ducts for the reception o tubular conduits', said'cylindrical prlmary ducts being formed in the body of the bar alternately lon bpposite sides of said longitudinal row of noteholes, each of said laterally-disposed cylindrical primary ducts having one of said relatively small note-holes opening into yit at its side adjacent to the said longitudinal row of note-holes, each of said c lindrical ducts being also connected by a b eed-hole with a longitudinal tension-chamber together with said longitudinal tension-chamberl formed directly in the tracker-bar for the purpose described.'

5. In pneumatic apparatus, a tracker-bar formed in one piecewith a central longitudinal row of relatively small note-holes in its' face, with a series of relatively large cylindricalprimary ducts for the reception of tubular condults, said cylindrical primary ducts being formed in the body of the bar by boring through the under side of said bar on opposite sides of said central longitudinal row of note-holes, which latter are bored through the thin web left at the face of the bar, each note-hole entering one of the said cylindrical ducts on the side thereof adjacent .to the said longitudinal row of note-holes,

said tracker-bar also having a longitudinal vtension-chamber formed directly in each side wall, and each of said tension-chambers being connected by bleed-holes with the cylindrical primary ducts on that particular side of the central row of ynote-holes, whereby the spaces between the adjacent cylindrical ducts and the distancebetween adjoining noteholes is reduced to the minimum, for the pur- GEORGE l?. BRAND.

Witnesses:

GEO. WM. MrAr'r, D. W. GARDNER.

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